Adhesively attached resilient safety device for electrical connectors



'Aug. 17,1965

INVENTOR.

' G. J. RUBENS TACHED RESILIENT SAFETY ELECTR L; CONNECTORS Filed July1964 ADHESIVELY AT DEVICE FOR United States Patent 3 201,740 ADHESIVELYATTAGHED RESILIENT SAFETY DEVICE FOR ELECTRICAL CONNEYCTGRS George J.Rubens, Woodland Hills, Calif.

(8304 Melody Court, Bethesda, Md.) Filed July 17, 1964, Ser. No. 383,477Claims. (Cl. 339-40) This invention relates to safety devices forelectrical connectors, and more important to a safety device capable ofbeing adhesively attached to one half of a separable electricalconnector for protecting the user from accidental electri'cal shock or achild while tampering there- This invention is related to my pendingpatent application Serial No. 158,254 filed December 11, 1961, forResilient Safety Sleeve for Electrical Prongs, issued as Patent No.3,147,055.

My prior patent application set forth the hazards, especially tochildren, present during the connecting and disconnecting of electricalconnectors having male prongs. This condition arises because the prongsare initially energized when partially mated being open to accidentalcontact by the fingers of the user. My prior patent application covers acompressible protective device that is frictionally retained on the malehalf of the connector.

The present invention is directed to a similar protective device that isadhesively secured to one of the connector halves. In one embodiment theprotective device is in the form of a sleeve that encircles the prongsand is adhesively secured to the end wall of the electrical plug body.In another embodiment the compressible protective device is in the formof a plate or sheet of compressible material, adhesively attached to awall outlet, which has an additional feature of blocking the femalesocket from the inquisitive investigations of a child.

' One object of this invention is to provide a device that can beadhesively attached to one of the connector halves of a prong-typeconnector for protection against the energized prongs of the connectorduring the connecting and disconnecting operation.

Another object is to provide such a device that can be attached eitherto the female wall socket, or the male plug of a separable connector.

A further object is to provide such a protective device for separableconnectors that can be made simply and inexpensively, such as by astamping operation.

A still further object is to provide a resilient and compressibleprotective device that can be secured over a female wall socket to coverthe openings therein, serving the function of blocking the prongopenings, much like a shutter, until it is knowingly uncovered by auser, and which also functions to protect the user from accidentalengagement with the energized prongs during connector engagement anddisengagement.

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawings wherein:

FIG. 1 is an exploded view of a conventional male connector plug havingprongs and a resilient protective device in section having an adhesivebacking at one end capable of securing the device to the plug accordingto the teaching of this invention;

FIG. 2 is similar view of the assembled plug and device of FIG. 1connected to a female wall socket;

FIG. 3 is a front elevation view of a modified protective deviceadhesively secured to a wall cover plate, with a corner of the devicepeeled back;

FIG. 4 is a cross-section taken along line IV-IV of FIG. 3; and

3,201,740 Patented Aug. 17, 1965 FIG. 5 is a modified arrangement of theprong slots in I the protective device, partially illustrated, asrelated to the prongs openings in the wall socket.

Referring to the drawing where like reference numerals refer to similarparts throughout the drawing there is shown in FIG. 1 a conventionalelectrical plug it} having two or more prongs 12. According to theteaching of this invention a protective device 14 is constructed in formof a sleeve with a bore opening 16 adapted to receive prongs 12.Protective device 14 is made, as disclosed in my prior patentapplication, of any insulating material having a high degree ofcompressibility and resilience, such as polyvinyl chloride, neoprene,sponge rubber etc. which also has a low compression set. Both thesurfaces of bore opening 16 and outer periphery 17 are preferablyconcentric, that is they contain straight lines which are parallel topermit the device 14 to be easily and cheaply fabricated by stampingfrom a flat sheet of the desired material. The thickness of protectivedevice 14 in an uncompressed condition extends for the exposed length ofprongs 12 when initially energized to insulate the prongs whenever theyare hot, and throughout compression of the sleeve by the plug. In myprior patent application, the protective device is secured on the prongsby a restriction or by making the diameter of the bore opening less thanthe distance between the prongs so that the protective devicefrictionally engages the prongs.

In the present patent application protective device 14 is secured to theplug by an adhesive coating 18 applied to one end wall of the device andadapted to engage an .end wall 20 of the plug. A protective throw-awaycover sheet 22 protects the adhesive coating 18 prior to use. Thus inthe instant patent application bore opening 16 of the protective devicecan fit loosely over the prongs, but as a practical matter the sleevewall should be sufficiently thickto prevent it from being readily peeledback from the prongs by a child while in the energized condition toexpose the hot prongs. As previously indicated the outside wall and borewall should be concentric and parallel to permit inexpensive fabricationby stamping from a sheet of suitable material, instead of a moreexpensive molding operation which also could be used, if desired.

Upon removal of protective sheet 22, prongs 12 can be threaded throughprotective sleeve 14 and the sleeve adhesively secured to the end wallof plug 10. With the protective sleeve thus assembled to plug 1%, theplug can be connected to wall socket Z3, and the protective sleeve 14will insulate the prongs in any energized position in the connecting anddisconnecting operation.

FIGS. 3 to 5 illustrate a modification in which the protective device 24is applied to the escutcheon or wall plate 26 of a female wall socket23. In this application, device 24 serves an additional purpose ofblocking or sealing the prong openings 30 from the inquisitive probingof a child, as well as for the purpose of insulating the hot prongs ofthe male connector during the connecting and disconnecting operation asdoes the modification of FIGS. 1 and 2. In other words the modificationsof FIGS. 3 to 5 achieves a two-fold safety objective.

Protective device 24 is in the form of a sheet of the same material andthickness as in the above described modification. For standard plugsthis thickness should be between A" to /3". The outer configuration ofdevice 24 is not critical, except as a matter of convenience. If it ismade approximately the same size, or slightly less, than the outerconfiguration of the wall plate 26 which come in standard sizes, it willaid in the aligning the device with respect to the outlet, which isimportant as will be subsequently described. Safety device 24 is bestsecured to the wall plate through a pressure sensitive adhesive 32. Aband of the adhesive is applied preferably around the periphery of theback side of the sheet, leaving the central portion adjacent the wallsocket fill of adhesive. Safety device 24 can be of a size toaccommodate any conventional size outlet socket, a two outlet size beingillustrated. However, it is apparent that safety device 24 could be cutin half with a scissors transversely the center if only one socket needbe accommodated in which case it may be desirable to provide a centralband ofadhesive 34 to enable both halves of the safety device to beusable. A suitable protective cover means, not shown, for protecting theadhesive material should be provided.

A number of slots 36, corresponding to the number of prongs of theconnector to be accommodated, are formed extending completely throughsafety device 24, a two prong connector being illustrated. Slots 36 canbe formed during the same cutting operation that stamps out safetydevice 24, thus assuring a simple and inexpensive manufacture. Ifdesired, it is apparent the safety device of FIGS. 3-5 can be fabricatedby molding instead of stamping.

It should be noted that when the safety device is attached over thesocket, slots 36 in safety device 24 should be off-set from thecorresponding socket openings 30, shown in broken lines in FIGS. 3 and5, for the purpose of blocking or sealing openings 30. In other words,with safety device 24 in a relaxed position applied to wall plate 26,slots 36 and openings 30 in the respective elements are not intended tobe in alignment. This misalignment is designed for the purpose ofdiscouraging a child from playing with a plug or inserting anelectrically conductive object that could easily cause a painful burn,if not a fatal shock. In order to achieve alignment it is necessary forthe responsible user to distort the material of the safety deviceadjacent the socket 28, in one of several ways, to force slots 36 intoalignment with openings 30.

In FIGS. 3 and 4, this misalignment is achieved by laterally off settingslots 36 to one side (i.e. to the right side in FIG. 3) of socketopenings 30, in the order of a quarter of an inch more or less dependingon the resiliency of the material. This will require the user to insertthe prongs of the plug through safety device 24 until the prongs hitwall plate 26, necessitating the user to move the plug laterally to theleft until prongs 12 engage openings 30, at which time the plug prongscan be fully inserted into the socket. In this condition the material ofthe safety device is slightly distorted in a lateral direction until atime when the plug is pulled out at which time the resilient materialsprings back to its normal relaxed condition covering openings 30 asillustrated. Thus, the ability of the material of safety device 24 tospring back to its original state is utilized in two ways, underdistortion just described as well as straight compression as originallydescribed.

FIG. 5 shows an identical construction as in FIG. 3 except for amodified arrangement of slots 36 in protective device 24 relative tosocket openings 30. In FIG. 5 slots 36 are rotated 90 from openings 30,in other Words,slots 36 lie in normal relation to openings 30. In thismodification, after the plug is initially inserted through slots 36 theplug (and surrounding material of protective device 24) is rotated 90 ineither direction until the plug prongs 12 are aligned with openings 30to permit full'insertion. It is believed that the rotational maneuver isa little more complex to a child than a straight lateral movement, andhence, may represent a greater safety factor, although a greaterdistortion of the resilient material occurs in a rotational distortionthan in a lateral distortion. 1

Since in either modifications in FIGS. 3 and S, the resilient materialof the protective device must be distorted in the immediate vicinity ofthe slots 36, it is believed that the back of the material in this areashould be left free of adhesive 32 to permit readily such distortion andspring-back, and to avoid possible tearing the resilient material.

Installation of the protective device over any electrical wall outlet isquite simple. First the correct size protective device is selected forthe particular outlet, type and number of sockets, involved. Theprotective backing is removed from the adhesive and the devicecentective device will camouflage the outlet from, the in-.

tered over the outlet wall plate. Making the wall plate and protectivedevice about the same dimension assures that the slots 36 in theprotective device will be. properly positioned offset from socketopenings 30. The proprotected by the material from accidentally touchingthe hot prongs by the thickness of the material which is surrounding theprongs. The resiliency of the material is such that the plug will remainfrictionally engaged with the socket until intentionally removed, at

T which time the material will spring-back to its original thickness andoriginal orientation, ready for the next connection. It should be notedthat either or both of the outlets can be used without affecting eachother or the protective features of the device.

If desired, the exterior surface of protective device 24 could becolored or given a decorative appearance or' configuration.

The adhesive should be sufliciently tenacious to avoid being readilypulled off by a small child, but capable of being peeled off by an adultwhen permanent removal is desired, or for repairs on the socket. Thecorners of the protective sheet could be made rounded to discouragegripping by a child.

I claim:

1. The combination of an electrical connector plug having a body withexposed prongs extending from one end wall thereof, and a female socketconnector having openings to receive said prongs, said female sockethaving a wall escutcheon plate mounted thereabout, and a safety devicefor insulating said prongs when energized from contact With the fingersof a user and normally covering said socket openings when not in use,said safety device constructed in form of a sheet material having athickness extending for the length of the exposed prongs when initiallyenergized, said sheet having a plurality of apertures extending throughthe thickriess corresponding to the number of prongs on the plug, saidsheet being made of an insulating material having 7 a high degree ofcompressibility capable of being squeezed by the plug when inserted intothe socket precluding contact between the energized prongs and the usersfingers one wall surface of said sheet having an adhesive coatingsecuring the sheet to the wall plate, the area of said sheet oppositethe female socket being free of adhesive, said safety device beingsecured to the escutcheon plate so that the prong apertures are in anon-aligned position with the socket openings, whereby it is necessaryfor the user to insert the plug through the safety device and then movethe plug and the sheet material adjacent thereto until the prongs becomealigned with the socket openings for energization thereby.

2. A safety device for mounting between an electrical plug having prongsand a Wall socket having an escutcheon plate, comprising a sheet ofinsulation material having a Wall surface adapted to cover said socket,said material being made of uniform thickness, said material having aplurality of individual openings extending through said thickness oneopening for each prong of the plug, said material having a high degreeof compressibility capable of being squeezed by the plug when insertedinto the socket, said wall surface of the sheet of material having anadhesive coating for securing the periphery of said sheet to saidescutcheon plate, an area of said wall surface around the openings beingfree of adhesive to permit said area to be moved relative to said socketWhen the plug is inserted therein.

3. The safety device of claim 2 wherein the thickness of the material isin the order of A" to /8".

4. The combination of a female socket connector having prong openingsmounted in an escutcheon plate,

and a safety device, said female socket connector adapted to receive theprongs of a male plug, said safety de vice constructed in the form of asheet of insulating material having a high degree of compressibility,said sheet of insulating material having a plurality of individualopenings extending therethrough, one opening for each prong of the plug,said sheet of insulating material adhesively secured to the escutcheonplate, said sheet of insulating material when in a secured relaxedcondition oriented on the escutcheon plate so that the openings in thesafety device are in a non-aligned position with respect to the openingsin the female socket.

5. The combination of claim 4 wherein the outer configuration of thesafety device conforms substantially to the outer configuration of theescutcheon plate.

References Cited by the Examiner UNITED STATES PATENTS 2,281,739 5/42Wright 339-189X 2,455,582 12/48 Hoessel 339-41 2,458,153 1/49 Festge.

2,477,803 8/49 Huber 33940 2,650,262 8/53 Abbott 174-66 2,759,160 8/56Kelley 33960X 2,820,842 1/58 Meistrell 33940X 3,147,055 9/64 Rubens339-36 JOSEPH D. SEERS, Primary Examiner.

DONLEY J. STOCKING, Examiner.

2. A SAFETY DEVICE FOR MOUNTING BETWEEN AN ELECTRICAL PLUG HAVING PRONGSAND A WALL SOCKET HAVING AN ESCUTCHEON PLATE, COMPRISING A SHEET OFINSULATION MATERIAL HAVING A WALL SURFACE ADAPTED TO COVER SAID SOCKET,SAID MATERIAL BEING MADE OF UNIFORM THICKNESS, SAID MATERIAL HAVING APLURALITY OF INDIVIDUAL OPENINGS EXTENDING THROUGH SAID THICKNESS ONEOPENING FOR EACH PRONG OF THE PLUG, SAID MATERIAL HAVING A HIGH DEGREEOF COMPRESSIBILITY CAPABLE OF BEING SQEEZED BY THE PLUG WHEN INSERTEDINTO THE SOCKET, SAID WALL SURFACE OF THE SHEET OF MATERIAL HAVING ANADHESIVE COATING FOR SECURING THE PERIPHERY OF SAID SHEET TO SAIDESCUTCHEON PLATE, AN AREA OF SAID WALL SURFACE AROUND THE OPENINGS BEING